Duplication and Remolding of tRNA Genes in the Mitochondrial Genome of Reduvius tenebrosus (Hemiptera: Reduviidae).
Duplication and Remolding of tRNA Genes in the Mitochondrial Genome of Reduvius tenebrosus (Hemiptera: Reduviidae).
复制标题
Reduvius tenebrosus（半翅目：Reduviidae）线粒体基因组中 tRNA 基因的复制和重塑
DOI：
10.3390/ijms17060951
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发表时间：
2016-06-16
影响因子：
5.6
通讯作者：
Cai W
中科院分区：
文献类型：
--
作者：
Jiang P;Li H;Song F;Cai Y;Wang J;Liu J;Cai W
大多数食虫是捕食者，是害虫的重要天敌。这些昆虫的线粒体（mt）基因组是双链环状dna，编码37个基因。在本研究中，我们探索了红毛猴（Reduvius tenebrosus） mt基因组中tRNA基因的重复和重排。红毛猴是红毛猴亚科的第一个mt基因组。基因顺序由CR（控制区）-trnI-trnQ-trnM-ND2重新排列为CR- trnq - trni2 - trni1 - trnm - nd2。共鉴定出23个tRNA基因，包括22个昆虫中常见的tRNA基因和一个与trnM序列相似性较高的trnI基因（trnI2）。在基因重排热点区（控制区与ND2之间）发现了伪trni、伪cr、伪ND2等伪基因。这些特征为这种新的基因序列可以用串联重复/随机丢失（TDRL）模型解释提供了证据。tRNA复制/反密码子突变机制进一步解释了trnI2的存在，trnI2是在TDRL过程中由复制的trnM重塑而来（通过CAT到GAT的反密码子突变）。我们的研究也提出了新的问题，即这两个事件是否同时进行，以及重塑的tRNA基因是否完全起作用。值得注意的是，线粒体基因组中重复的tRNA基因在刺客虫体内至少独立进化了两次。
Most assassin bugs are predators that act as important natural enemies of insect pests. Mitochondrial (mt) genomes of these insects are double-strand circular DNAs that encode 37 genes. In the present study, we explore the duplication and rearrangement of tRNA genes in the mt genome of Reduvius tenebrosus, the first mt genome from the subfamily Reduviinae. The gene order rearranges from CR (control region)-trnI-trnQ-trnM-ND2 to CR-trnQ-trnI2-trnI1-trnM-ND2. We identified 23 tRNA genes, including 22 tRNAs commonly found in insects and an additional trnI (trnI2), which has high sequence similarity to trnM. We found several pseudo genes, such as pseudo-trnI, pseudo-CR, and pseudo-ND2, in the hotspot region of gene rearrangement (between the control region and ND2). These features provided evidence that this novel gene order could be explained by the tandem duplication/random loss (TDRL) model. The tRNA duplication/anticodon mutation mechanism further explains the presence of trnI2, which is remolded from a duplicated trnM in the TDRL process (through an anticodon mutation of CAT to GAT). Our study also raises new questions as to whether the two events proceed simultaneously and if the remolded tRNA gene is fully functional. Significantly, the duplicated tRNA gene in the mitochondrial genome has evolved independently at least two times within assassin bugs.